The present invention relates to a ship for transporting coal slurry.
Generally coal is transported by land from coal mining areas to loading ports, where it is loaded into ships for transport by sea. To reduce the cost of transport by land and also to assure an efficient loading operation at the port, it is frequent practice in recent years to disperse pulverized coal in water in the mining area to obtain a coal slurry, transport the coal slurry to the port through a pipeline and thereafter load the slurry into a ship also through a pipeline. This method is very advantageous in that coal can be automatically loaded into the ship with use of a floating hose or the like which is supported by a buoy and connected to a facility on the shore without mooring the ship alongside a wharf. However, the usual coal slurry to be loaded into ships by pipelines contains, for example, about 50 to 70% by weight of water, so that the coal slurry is inefficient to transport as it is and requires a prohibitively high transport cost since the amount of coal that can be loaded into the ship is smaller by an amount corresponding to the water content. To enable the ship to transport coal with an improved efficiency, it is required to drain the coal slurry in its holds to the greatest possible extent and thereby load the ship with as much coal as possible. Further as an increasing amount of coal is loaded into the hold, coal particles settle, permitting a portion of the slurry water to collect above the mass of coal particles. Accordingly if the ship rolls while transporting the coal slurry in this state, the overlying portion of slurry water heaves to pose the hazard of pronounced rolling or is likely to strike against the hatch cover or flow out from the hold. Such a problem similarly arises also when the ship rolls during loading. The slurry water collecting above the mass of coal particles during loading must therefore be discharged as promptly as possible in order to eliminate the above objection and to assure an efficient slurry loading operation.
The coal slurry placed into the hole is dewatered generally through drain outlets equipped with a filter and provided in the bottom of the hole, but it is difficult to efficiently discharge from the bottom drain outlets the slurry water which collects above coal particles during loading. Thus the conventional ships for transporting coal slurry have the problem that they are not adapted for an efficient loading operation.